Heterotopic mesenteric ossification: a report of two cases

Hisham F. Bahmad,Olga Lopez,Tyson Sutherland,Marisa Vinas,Kfir Ben-David,Lydia Howard,Robert Poppiti,Sarah Alghamdi 대한병리학회 2022 Journal of Pathology and Translational Medicine Vol.56 No.5

Heterotopic mesenteric ossification (HMO) is abnormal bone formation in tissues which usually do not undergo ossification. There are approximately 75 cases reported worldwide. We present two cases of HMO. The first case is that of a 39-year-old man who presented with abdominal pain and a computerized tomography scan of the abdomen and pelvis revealed an apple core lesion resulting in small bowel obstruction. The second case is that of a 36-year-old woman who presented 2 months after undergoing robotic gastric sleeve resection complaining of weakness and emesis. An esophagogram revealed kinking at the distal esophagus. Surgical resection was performed in both, yielding the diagnosis of HMO. There are various theories as to the pathophysiology of HMO, but no clearly defined mechanism has been established. Management should be conservative whenever possible to prevent further ossification with subsequent surgical intervention.

First-principles calculations to investigate structural, optoelectronic and thermoelectric properties of Sn-based halide perovskites: CsSnCl3 and CH3NH3SnCl3

Selmani Y.,Labrim H.,Bahmad L. 한국세라믹학회 2024 한국세라믹학회지 Vol.61 No.1

The structural, electronic, optical and thermoelectric properties of inorganic CsSnCl3 and organic–inorganic CH3NH3SnCl3 cubic perovskites have been calculated using first-principles calculations. Structural properties were studied using the generalized gradient approximation (GGA) of the Perdew Burke Ernzerhof (PBE) function. Electronic calculations such as density of states (DOS) and band structures (BS) reveal that inorganic CsSnCl3 and organic–inorganic CH3NH3SnCl3 perovskites exhibit direct band gaps of 1.15 eV and 1.98 eV, respectively. The results of optical properties such as optical absorption show that the studied materials have high light absorption in the visible region. In addition, the effects of temperature on thermoelectric parameters such as Seebeck coefficient, electronic figure of merit, electrical and electronic thermal conductivities, power factor and figure of merit were calculated and discussed. This theoretical study of electronic, optical and thermoelectric properties could make inorganic CsSnCl3 and organic–inorganic CH3NH3SnCl3 perovskite materials potential candidates for optoelectronic applications energy conversion technologies.

Study of the solar perovskites: XZnF3 (X = Ag, Li or Na) by DFT and TDDFT methods

Idrissi S.,Mounkachi O.,Bahmad L.,Benyoussef A. 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.2

In this work, we have applied the density functional theory (DFT) and time-dependent density-functional theory (TDDFT) to study and discuss the different properties of the inorganic perovskites XZnF3 (X = Ag, Li or Na). In fact, we have presented the structural, electronic and optical properties of the Halide Perovskite XZnF3 (X = Ag, Li or Na). Such materials are in great demand for solar cell uses. To conduct this study, we have applied the Quantum Espresso package using the two methods: GGA–PBE and GGA–PBESol. The different lattice parameter a (Å) values have been used to deduce the energy optimum of the perovskites XZnF3 (X = Ag, Li or Na). Besides, the total and partial density of states (DOS) and the band structure of these materials have been illustrated for the two situations: in the presence and the absence of the Spin Orbit Coupling (SOC) approximation. To complete this study, we have presented the optical properties of the XZnF3 (X = Ag, Li or Na) materials. In fact, such properties have been investigated when exploring the real and imaginary parts of the corresponding dielectric function. To reach this goal, we have applied the two approximations: the GGA–PBE and GGA–PBESOL. Our results reveal high transparency of the electromagnetic radiations in the energy range between (0.0 ħω) Ry and (0.25 ħω) Ry. A notable peak of the imaginary part, has been found at about (0.15 ħω) Ry for the studied materials, confirms the transition from the top of valence band to the bottom of conduction band.

Post-mortem assessment of vimentin expression as a biomarker for renal tubular regeneration following acute kidney injury

Juan Carlos Alvarez Moreno,Hisham F. Bahmad,Christopher A. Febres-Aldana,Andrés Pirela,Andres Azuero,Ali Salami,Robert Poppiti 대한병리학회 2021 Journal of Pathology and Translational Medicine Vol.55 No.6

Background: Acute kidney injury (AKI) is a common cause of morbidity and mortality. It mainly targets the renal tubular epithelium with pathological changes, referred to as acute tubular injury. The latter is followed by a regenerative response that is difficult to visualize on routine hematoxylin and eosin (H&E) stains. In this study, we examined the regenerative capacity of renal tubules by correlating vimentin (VIM) immunohistochemical (IHC) expression and pathological findings of AKI and renal tubular regeneration (RTR) on H&E.Methods: We reviewed 23 autopsies performed in the clinical setting of AKI and RTR. VIM expression was scored in the renal cortical tubular epithelium using a statistical cutoff ≥ 3% for high expression and < 3% for low expression.Results: Of the 23 kidney tissues examined, seven (30.4%) had low VIM expression, and 16 (69.6%) had high VIM expression. Kidney tissues with evidence of AKI and RTR had significantly higher VIM expression. Renal peritubular microenvironment features showing regenerative changes on H&E were associated with high VIM expression. In the univariate model, kidney tissues with RTR were 18-fold more likely to have high VIM expression.Conclusions: In conclusion, our findings suggest that VIM could serve as an IHC marker for RTR following AKI. However, correlation with H&E findings remains critical to excluding chronic tubular damage. Collectively, our preliminary results pave the way for future studies including a larger sample size to validate the use of VIM as a reliable biomarker for RTR.

Prevalence, Laboratory Findings and Clinical Characteristics of Campylobacteriosis Agents among Hospitalized Children with Acute Gastroenteritis in Lebanon

Ghssein, Ghassan,Awada, Rana,Salami, Ali,Bahmad, Hisham F.,Awad, Ali,Joumaa, Wissam H.,Roz, Ali El The Korean Society of Pediatric Gastroenterology 2021 Pediatric gastroenterology, hepatology & nutrition Vol.24 No.4

Purpose: Campylobacter species are currently the most common cause of bacterial gastroenteritis. In Lebanon, Campylobacter infection occurrence is underdiagnosed owing to the lack of specific culture and rapid test kits, particularly among children. This study aimed to evaluate the prevalence, laboratory findings, and clinical characteristics of Campylobacter infection in hospitalized children with acute gastroenteritis in South Lebanon. Methods: We conducted a 6-month retrospective cohort study between January and June 2018, including 291 children aged between 1 month and 12 years, who were admitted to a tertiary healthcare center in South Lebanon. The medical files of the patients were reviewed to retrieve the required clinical information, including clinical and laboratory data. Results: The prevalence of campylobacteriosis agents in pediatric patients with acute gastroenteritis is 12.02%. Patients infected with Campylobacter had more severe acute gastroenteritis than Campylobacter-negative patients and often presented with high-grade fever, diarrhea episodes more than six times per day, diarrhea lasting for more than five days, and dehydration. Indeed, children with high-grade fever (≥38.5℃) were five times more likely to test positive for Campylobacter than those with low-grade fever. In addition, the results showed a higher Vesikari score for the majority of Campylobacter-positive patients with severe acute gastroenteritis compared to a moderate profile for Campylobacter-negative patients. Conclusion: The present study findings highlight that Campylobacter infection is frequent among children with acute gastroenteritis. Therefore, the detection of Campylobacter should be carried out for the diagnosis of human gastroenteritis in Lebanon, along with the detection of routine enteropathogens.